Question

If Ram travels to his school from his house at the speed of $3$ km/hr, then he reaches the school $5$ minutes late. If he travels at the speed of $4$ km/hr, then he reaches the school $5$ minutes earlier than school time. The distance of his school from his house is

• A. $1$ km
• B. $2$ km
• C. $4$ km
• D. $6$ km

Answer 1

The correct option is B $2$ km

Let the distance between school and house be $x$ km.
The difference of time $=10$ minutes $=\frac{10}{60}$ hour
Now, $\frac{x}{3}-\frac{x}{4}=\frac{10}{60}$
$\Rightarrow \frac{x}{12}=\frac{1}{6}$
$\Rightarrow x=2$
Hence, the distance of his school from his house is $2$ km.